An anastomosis is a connection between two anatomical structures. For example, blood vessels severed during an organ transplantation can be connected to one another by anastomoses.
In surgery, various methods for producing such anastomoses are known. For example, the connection can be made using suturing techniques. Inserts also exist that permit an organic connection by adhesive techniques. In this context, fibrin glues are often used, which enable the very advantageous connection of organs, particularly hollow organs. However, the tolerability of such adhesives is problematic, since they can have thrombogenic and toxic properties.
Clamping techniques are also used to create a connection at a suitable site. Various aids, such as rings, cuffs or stents are used to assist in the production of anastomoses.
It is disadvantageous, however, that these aids usually remain in the hollow organ being connected and can cause rejection reactions or increase the risk of thromboses.
WO 03/061487 A1 discloses connecting hollow organs by the application of a suitable high frequency (HF) current. When the HF current is applied, biological welding of the tissue structures takes place. The cellular substance coagulates with the result that the protein structures adhere, so that a controlled, secure and rapid connection can be created. WO 03/061487 A1 provides an instrument for the application of an HF current, said instrument comprises an inner sleeve and an outer sleeve. These sleeves each comprise an electrode, which is ring-shaped, to which the HF current is supplied. This instrument is a bipolar HF instrument. To connect the ends of a blood vessel, the first end is guided through the inner sleeve and is folded over such that the tissue comes to lie against the outside of the inner sleeve. The second end of the vessel is pulled over the inner sleeve and the end section of the blood vessel situated thereon. The outer sleeve can be opened and placed over the inner sleeve and the tissue situated thereon. The electrodes are arranged on the sleeves such that the first and second ends of the vessel are clamped between the electrodes on the sleeves. On application of the HF current, said current flows through the tissue and welds the ends.
A problem with WO 03/061487 A1 lies in the fact that in order to weld or coagulate hollow organs having different diameters, a plurality of differently configured instruments is needed. In particular, the gap between the electrodes and the sleeves must be dimensioned so that it is matched to the thicknesses of the walls.
Only when the electrodes are optimally placed on the tissue structures does the advantageous welding of the tissue structures take place. The coagulation procedure requires continuous pressure on the tissue structures or vessel end sections throughout the coagulation process.
The results finally achieved with the instrument disclosed in WO 03/061487 A1 are strongly dependent on the choice of a suitable instrument, i.e. on the judgment of the treating physician and are therefore difficult to document and reproduce.